lack of return from static method doesn't cause error

[DartBot]

This issue was originally filed by domi...@google.com

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This code passed through analyzer, the dart vm, dart2js, and ran in dartium.

Vector {
  num x, y, z;
  Vector(this.x, this.y, this.z);
  static Vector normalize(Vector v) {
    if (v.length != 0.0)
      return Vector.multiply(v, 1.0 / length);
  }

It was only when I passed in Vector(0, 0, 0) that I tickled the bug and received back an undefined Vector from the JS version.

[lrhn]

It should never be an error, since a function reaching the end of its body implicitly returns null.
Actually the spec says that is implicitly adds a "return null;" statement. That should probably be changed to an implicit "return;" statement, since the former will hide the problem here.

I think this should cause a static type warning, but as the spec is written, the "return null;" doesn't cause a warning. Had it been just "return;" it would be a static warning because the type "void" is not assignable to "Vector".

[lrhn]

Added Area-Language label.

[dgrove]

Set owner to @gbracha.
Added Triaged label.

[sethladd]

Added Duplicate label.
Marked as being merged into #73.